In patients with advanced volume overload, minimally invasive ultrafiltration treatment in the acute phase can have a positive effect on clinical outcome. The aim is to collect treatment data in the context of a prospective registry of the safety and performance of minimally invasive ultrafiltration. The data will be recorded via an electronic case report form (eCRF); the eCRF runs on a server located in Germany and complies with current data protection regulations. It is intended to include about 300-500 patients with advanced volume overload at a minimum of 10 sites. In addition, data on a disease management programme (in-body measurement and home monitoring) will be recorded in up to 40 of these patients. The treatment data from each patient will be recorded over 12 months. An interim analysis will be performed after 150 patients have been observed for 6 months. The knowledge about ultrafiltration in volume overload obtained from the registry, in some cases in combination with a disease management programme, is intended to improve the body of evidence. In addition, the data will be used for hypothesis generation.